GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you review the Instrument Cluster Circuit Description and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Instrument Panel, Gages and Console

2

Verify that the engine coolant temperature gauge is inoperative.

Does the engine coolant temperature gauge operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Disconnect the engine coolant temperature (ECT) sending unit connector.
  2. Connect a fused jumper from connector cavity 2 to chassis ground.

Does the ECT gauge indicate C?

Go to Step 4

Go to Step 5

4

Replace the ECT sending unit. Refer to Fuel/Temperature Gage Replacement

Did you complete the repair?

Go to Step 10

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5

  1. Disconnect the instrument panel cluster assembly connector C3 cavity 4.
  2. Test for open condition between cavity 4 and battery+

Is an open condition present?

Go to Step 6

Go to Step 7

6

Repair the open in the YEL/WHT wire between the instrument panel cluster assembly and the ECT sending unit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 10

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7

Inspect the instrument panel cluster printed circuit for any damage or loose connections. Refer to Printed Instrument Cluster Circuit Replacement .

Does damage or loose connections exist?

Go to Step 8

Go to Step 9

8

Replace the instrument panel cluster printed circuit. Refer to Printed Instrument Cluster Circuit Replacement .

Did you complete the repair?

Go to Step 10

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9

Replace the ECT gauge. Refer to Fuel/Temperature Gage Replacement .

Is the repair complete?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3